Let's be more generous than that. Let's say everyone needs at least $27,000 per year. 150,000,000 people make less than $27,000 a year. Let's assume they make an average of $13,500 a year. A reverse income-tax would need to double that to allow everyone to pay for the cost of living. So, we need to budget for $2.1 trillion. If we decreased our military budget to the per capita rate of developed countries we get $1.14 trillion. (We spend $1.3 trillion, most developed countries spend $550 per person, or $0.16 trillion for a country the size of the U.S.). If we closed other means-tested welfare programs, we get $0.93 trillion. If we closed social security, we get $0.78 trillion. If we closed corporate tax loopholes, we get $0.15 trillion. Who knows what we'd get if we reinstated the tax rates from the '50s through the '70s, or if we stopped spying on everyone, or if we stopped imprisoning so many people for so long, but we already have more than enough: $3 trillion. I think we the reason we aren't already doing this is because of our priorities, not because we can't afford to.